Myrsine aquilonia is a dioecious, suckering shrub or small tree up to 12 m tall with an erect and spreading, crowded branching habit. Aquilonia means northern, referring to the natural distribution of coastal matipo, which is found on Rauhomaumau Island, in Tutukaka, Rangaunu Harbour, and Te Arai in the far north of New Zealand. It is scarce on the mainland, however, and is found most abundantly on the Poor Knights Island group where it is often the co-dominant species in the main vegetation types. Adult leaves (12­28 x 10­17 mm) are thick, dark green, and semi-glossy with a rounded or obtuse apex with a shallow notch. Tiny green flowers appear in August followed by circular purple or violet drupes in December – January.